The present disclosure relates to an optional device attachably/detachably attached to a main body of an image forming apparatus.
For example, an optional device has been known which is configured to be retrofitted to an existing image forming apparatus, such as a copier, and includes a tray accommodating a large number of sheets and a sheet feeding unit.
This optional device is attached to an image forming apparatus, in such a manner that the sheet feeding unit is arranged opposite a sheet receiving port of the image forming apparatus. The sheet feeding unit feeds a sheet out of the tray into the sheet receiving port, and the sheet fed into the sheet receiving port is then conveyed to a sheet conveyance portion. Thus, when there is not enough space for a large number of sheets in the image forming apparatus, sheets can be fed from the retrofitted optional device into the image forming apparatus.
The optional device is further provided with a connection member arranged on an opposing face of the optional device, the opposing face arranged opposite to the image forming apparatus. The connection member has an engagement hole to be engaged with a projection provided on an opposing face of the image forming apparatus, the opposing face arranged opposite to the opposing face of the optional device. Thereby, it is possible to attach the optional device to the image forming apparatus easily.